Smart machine wins national recognition

By Karl BatesCollege of Engineering

A dramatic improvement in the way machine tools are used to bore long holes in manufactured parts is being recognized by Industry Week magazine as one of the Top 25 Technologies of 1999. The prize announcement appeared in the Dec. 6 edition of the magazine.

The laser-guided BOAline-boring machine is a smart tool resulting from a three-year, $2 million collaboration between researchers at the College of Engineering and a private partner, Lamb Technicon of Warren. Engineers from Ford Motor Co., General Motors Corp. and the DaimlerChrysler Corp. also participated in the planning phase of the project. Three patentable inventions were created by the research, and the smart tool may reach the market in first-quarter 2001.

High-precision boring of the long holes in an engine block for camshafts and crankshafts has been a technical problem for decades, and a bottleneck in the move toward more agile manufacturing plants capable of producing several product lines at once. The boring machines, until now, have been dedicated to one task and one specific configuration, making the production of multiple engine configurations in the same plant require several machines, and slowing changeovers considerably, explains Phil Szuba, director of research and new product development at Lamb Technicon.

The BOA (Boring with Optimal Accuracy) process developed by Lamb and the U-M team makes these tools agile and flexible like never before, without sacrificing accuracy. If you think about using a very long drill bit, imagine how the end of it will tend to wobble or stray off course as it moves down a very long bore hole. Until now, boring machines have required some carefully aligned supports along the length of the engine block to keep the tool on target at tolerances of only thousandths of a millimeter. And those supports are part of what makes the machines unable to change tasks easily.

Zbigniew Pasek, the U-Ms operations manager for the project, explained that the heart of the new system is the machine tool itself, a long hollow drill bit. A pair of laser beams are aimed along the length of the hollow tools interior. They are focused on a tiny piezoelectric actuator at the tip of the tool that can steer if it senses a misalignment of the lasers. The actuator checks the alignment 1,000 times a second, and can make up to 30 corrections per revolution of the tool. This happens in real time, so its pretty tight, Szuba says.

Lambs engineers think a single machine equipped this way would be able to precision-bore at least six different engine configurations, a task that would require dedicating six of the old machines. It could trim production costs by $50 to $85 per vehicle, resulting in annual savings of $700 million to $1.2 billion for U.S. automakers.

In addition to creating a breakthrough technology, the joint research project has been fun and rewarding, Szuba says. We were able to get a lot done because the U-M kind of let the company come in and work directly with the graduate students, which resulted in great teamwork. Pasek says two students have earned Ph.D.s related to the project, and a third is nearing completion. Several undergraduate students also gained practical research experience working on the smart tool with Lamb.

Yoram Koren, director of the Colleges Engineering Research Center for Reconfigurable Machinery, said the industrial partnership with Lamb is the sort of project that U-M hopes to do more of. The center, which is developing new technologies for faster, more flexible manufacturing, operates on a $5 million annual budget, of which about 30 percent comes from industry.

The BOA project was funded by the National Institute of Science and Technologys Advanced Technology Program.